Matches in SemOpenAlex for { <https://semopenalex.org/work/W1978754515> ?p ?o ?g. }
Showing items 1 to 93 of
93
with 100 items per page.
- W1978754515 endingPage "150" @default.
- W1978754515 startingPage "114" @default.
- W1978754515 abstract "The Colorado River in its course from central Texas to the Gulf of Mexico carries quartz, chert, and limestone pebbles which can be traced for distances of up to 270 miles from their source. Limestone is so soft that it reaches its limiting roundness in the first few miles and thereafter undergoes no further increase. Harder quartz rounds much more slowly but eventually attains the same high limiting roundness value as limestone. Chert, being brittle, tends to spall and only rounds slightly downstream. A new and more behavioristic measure of equidimensionality, maximum projection sphericity, is introduced, and a triangular diagram is proposed for analysis of the equant versus disklike versus rodlike aspect of particles, here termed form. It was hoped that, by limiting the study to pebbles 32-64 mm. in length, the effects of grain size might be eliminated; the data show, however, that, even within this narrow range, particle size has a greater effect on sphericity and form than 200 miles of fluvial transport-larger pebbles tend to have lower sphericity and a rodlike form, while smaller ones are more discoidal. Limestone pebbles remain at constant low sphericity because of their bedding and show no significant change with distance. For quartz, pebbles larger than 54 mm. become more rodlike downstream but show little numerical change in sphericity, hence apparently roll like a rolling pin and wear chiefly on the intermediate axis. Quartz pebbles smaller than 38 mm. show a significant downstream increase in sphericity, chiefly by wear on the long axis, and hence must be carried chiefly in saltation where they bounce randomly along the bottom. Surprisingly, chert pebbles larger than 38 mm. show a striking downstream decrease in sphericity and become more bladed by diminution of the short axis, apparently by preferential splitting parallel with the bedding; but chert pebbles smaller than 38 mm. increase in sphericity in the same manner as do small quartz pebbles. For both quartz and chert, pebbles near the source have similar sphericity and form regardless of size; since large and small sizes wear by opposite mechanisms, there is increasing divergence in sphericity andform between large and small pebbles as they are traced farther from their source. Detailed analysis of the polymodal sphericity frequency distributions reveals the apparent existence of remarkably constant discrete sphericity populations for each rock type. Furthermore, for all rock types the intermediate axis tends to measure very close to halfway between the long and short axes-hence there is a dominance of bladed forms; this is true even for limestone, in which discoidal forms are but slightly more abundant than rodlike forms. Analysis of mean form on the triangular diagram seems to be the most powerful weapon available to attack the problem of particle abrasion. This study shows that sphericity depends most importantly on the inherent abrasional properties of the different rock types, is strongly a function of size as well as distance, and is but little affected by selective sorting." @default.
- W1978754515 created "2016-06-24" @default.
- W1978754515 creator A5022551934 @default.
- W1978754515 creator A5039874767 @default.
- W1978754515 date "1958-03-01" @default.
- W1978754515 modified "2023-10-16" @default.
- W1978754515 title "Pebbles in the Lower Colorado River, Texas a Study in Particle Morphogenesis" @default.
- W1978754515 cites W1613830915 @default.
- W1978754515 cites W1965282742 @default.
- W1978754515 cites W1975574393 @default.
- W1978754515 cites W1991063688 @default.
- W1978754515 cites W1995038960 @default.
- W1978754515 cites W2030475141 @default.
- W1978754515 cites W2051016497 @default.
- W1978754515 cites W2063436051 @default.
- W1978754515 cites W2071609558 @default.
- W1978754515 cites W2075149078 @default.
- W1978754515 cites W2100229578 @default.
- W1978754515 cites W2143370091 @default.
- W1978754515 cites W2150178633 @default.
- W1978754515 cites W2159525271 @default.
- W1978754515 cites W2164662095 @default.
- W1978754515 doi "https://doi.org/10.1086/626490" @default.
- W1978754515 hasPublicationYear "1958" @default.
- W1978754515 type Work @default.
- W1978754515 sameAs 1978754515 @default.
- W1978754515 citedByCount "650" @default.
- W1978754515 countsByYear W19787545152012 @default.
- W1978754515 countsByYear W19787545152013 @default.
- W1978754515 countsByYear W19787545152014 @default.
- W1978754515 countsByYear W19787545152015 @default.
- W1978754515 countsByYear W19787545152016 @default.
- W1978754515 countsByYear W19787545152017 @default.
- W1978754515 countsByYear W19787545152018 @default.
- W1978754515 countsByYear W19787545152019 @default.
- W1978754515 countsByYear W19787545152020 @default.
- W1978754515 countsByYear W19787545152021 @default.
- W1978754515 countsByYear W19787545152022 @default.
- W1978754515 countsByYear W19787545152023 @default.
- W1978754515 crossrefType "journal-article" @default.
- W1978754515 hasAuthorship W1978754515A5022551934 @default.
- W1978754515 hasAuthorship W1978754515A5039874767 @default.
- W1978754515 hasConcept C109007969 @default.
- W1978754515 hasConcept C112959462 @default.
- W1978754515 hasConcept C114793014 @default.
- W1978754515 hasConcept C127313418 @default.
- W1978754515 hasConcept C127413603 @default.
- W1978754515 hasConcept C14190554 @default.
- W1978754515 hasConcept C151730666 @default.
- W1978754515 hasConcept C173913448 @default.
- W1978754515 hasConcept C188198153 @default.
- W1978754515 hasConcept C192191005 @default.
- W1978754515 hasConcept C199289684 @default.
- W1978754515 hasConcept C2524010 @default.
- W1978754515 hasConcept C2779870107 @default.
- W1978754515 hasConcept C33923547 @default.
- W1978754515 hasConcept C78519656 @default.
- W1978754515 hasConceptScore W1978754515C109007969 @default.
- W1978754515 hasConceptScore W1978754515C112959462 @default.
- W1978754515 hasConceptScore W1978754515C114793014 @default.
- W1978754515 hasConceptScore W1978754515C127313418 @default.
- W1978754515 hasConceptScore W1978754515C127413603 @default.
- W1978754515 hasConceptScore W1978754515C14190554 @default.
- W1978754515 hasConceptScore W1978754515C151730666 @default.
- W1978754515 hasConceptScore W1978754515C173913448 @default.
- W1978754515 hasConceptScore W1978754515C188198153 @default.
- W1978754515 hasConceptScore W1978754515C192191005 @default.
- W1978754515 hasConceptScore W1978754515C199289684 @default.
- W1978754515 hasConceptScore W1978754515C2524010 @default.
- W1978754515 hasConceptScore W1978754515C2779870107 @default.
- W1978754515 hasConceptScore W1978754515C33923547 @default.
- W1978754515 hasConceptScore W1978754515C78519656 @default.
- W1978754515 hasIssue "2" @default.
- W1978754515 hasLocation W19787545151 @default.
- W1978754515 hasOpenAccess W1978754515 @default.
- W1978754515 hasPrimaryLocation W19787545151 @default.
- W1978754515 hasRelatedWork W2004391928 @default.
- W1978754515 hasRelatedWork W2043966946 @default.
- W1978754515 hasRelatedWork W2137115519 @default.
- W1978754515 hasRelatedWork W2354221783 @default.
- W1978754515 hasRelatedWork W2964829420 @default.
- W1978754515 hasRelatedWork W2995946543 @default.
- W1978754515 hasRelatedWork W3208512759 @default.
- W1978754515 hasRelatedWork W4200201271 @default.
- W1978754515 hasRelatedWork W2506481558 @default.
- W1978754515 hasRelatedWork W2733331457 @default.
- W1978754515 hasVolume "66" @default.
- W1978754515 isParatext "false" @default.
- W1978754515 isRetracted "false" @default.
- W1978754515 magId "1978754515" @default.
- W1978754515 workType "article" @default.